Steam Networks

I'll note that powerplant steam turbines are often pretty cutting edge & supported by essentially a special plant to achieve this levels of efficiency and reliability. Stuff like hydrogen cooling the generator bit:

https://en.wikipedia.org/wiki/Hydrogen-cooled_turbo_generato...

And UBC

Could not find the answer, kept getting general pages about how much current a wire can pass (without the result even containing the keyword I looked for, like temperature or heat or warm). To still have some indication of whether this is an interesting thing to keep looking into, ChatGPT says:

> Typically, high-voltage transmission lines are designed to operate at temperatures of around 75 to 100°C (167 to 212°F). However, under heavy loads, they can sometimes reach up to 150°C (302°F), but this is usually the upper limit for safe operation.

If that's a core temperature then the insulation might not make it significant, but if the outside leaks this much... I might not mind paying myself for a plastic tube and a fan to use around the line if I lived near one. Okay okay, it'll be more complicated than that, but still: free energy? And you're doing the power company a favor by decreasing the resistance in the case of most metals (https://www.engineeringtoolbox.com/resistivity-conductivity-...) including copper which https://en.wikipedia.org/wiki/High-voltage_cable says they're made of

That's why they don't look at 1 person but at aggregates. If the world was made of twins and triplets and they lived identical lives (nutrition, stress levels, air quality, ...) besides the 1 factor you're interested in (fireplace yes/no), that would be great for learning from, but of course that's not the case, not even for that astronaut

I'd encourage you to open up one of these studies. The language in scientific papers is made to sound smart but it's still English (most of the time) and you'll see these sorts of things are established by looking at many people in many situations and then use maths to tease out how much each of the factors (living near a major road, for instance) contributes to the thing being investigated (such as longevity). Many of the factors, also depending on the number of people involved, will not turn out to be statistically significant, meaning that the error margins are too large to be sure. For smoking and woodfire particulates though, we're certain that it's unhealthy to within extremely low error margins. Whether that's precisely 18 minutes: probably not, but presumably that's our best guess, even if it has uncertainty associated with it. The paper is linked literally within the quote you gave, if you want to check how uncertain the value is: https://www.sciencedirect.com/science/article/pii/S235271022...

Skimming this one, they didn't establish the relation between particulate matter and lifespan themselves but they cite other studies that did this:

> correlating average PM2.5 levels during a shorter time interval and the average life expectancy during that same time period. In Taiwan, this method used data from 17 counties for the 2010 to 2017 period and resulted in a DLE factor of 0.798 years per 10 μg/m3-increase in exposure to PM2.5 [50]. Using data from 545 counties in the United States for between 2000 and 2007 [51] and data from 214 cities in China for between 2013 and 2017 [52], resulted in lower DLE factors: 0.14 and 0.18 years, respectively, per additional 10 μg/m3 of exposure to PM2.5.

If you doubt those methods, you should click through to sources 50, 51, and 52. This study just measured the amount of PM2.5 in three situations and then multiplied it with that value from the other studies (I didn't read far enough to see which one they ended up picking, that should be mentioned somewhere if you want to know/check it precisely), and that's how they get to this value

> There's just no real evidence this stat is true.

They don't just pull stats from thin air. If you think they made a mistake somewhere and arrived at the wrong number, I'm curious to hear where they went wrong, and the authors would probably be happy to be get an even better stat as well

The inefficiencies come from infrastructure. Transferring electricity is so goddamn cheap, that city planners and developers hardly consider it a footnote. Water, sewage and drainage on the other hand are much, much more expensive. They require much more space, and oft times need to be pressurized. Imagine that with steam pipes where the steam on top of all that, needs to be heated too. Sure, hooking up to an existing steam main probably doesn't cost too much, but building new mains can't be worth it, even in the long run, as infrastructure constantly needs to be upgraded.